What makes a person look as thought they lost 150 lbs without losing it??

[Diam0ndgirll]

I was always a very fit person. I am 53 years old but always looked much younger. About 5 years ago my entire body turned to mush over night!!  I no longer had any structure to my skin. My toned body was starting to sag everywhere!  It all happened quite suddenly. To make a long story short, it has continued to get worse. I now look like a person who has lost about 150 lbs. up until last August , I hadn't lost any. I was sick for about 2 weeks and hardly ate anything so I lost about 5 lbs. over the duration of this happening, i e sought out help from everyone!  I've had every muscular test there is including a spinal tap to rule out conditions as it appeared I lost all my muscle. All those tests were negative. I stated seeing a naturalpathic dr who informed me my hormone levels were no existent and started bio identical hormones. That was 2 years ago. I went to the mayo clinic in January of last year for a week. They said metabolic myopathy with also some complications of prednisone I was taking and my thyroid medication being off. Other than that they found nothing and tested everything. I recently had a mole on my leg that came back as severely untypical so I had it removed. The dr immediately got to my fat layer as she said my dermis layer was non existent. She phoned the pathology dept and asked they do further testing, they came back with some disorder but said I would have had to present as a child or teenager which I did not, so they had no clue what was wrong. I have had MRI of my stomach spine legs etc. no issues found that could relate to what's going on. I am a mess thinking there's something serious and no one is finding it. I'm wasting away to nothing even though the scales show a 5lb difference. I have given up dairy and don't eat anywhere near what I use to so that could account for the 5lbs. I've quit smoking 3 years ago, gave up Diet Coke and take more supplements than I can afford. I am desperate for some help so if anyone can offer advice I would greatly appreciate it. What is my body missing??